Recent research indicates that infants can draw on at least two sources of information to individuate objects involved in occlusion events: (a) featural (i.e., the shape, size, color, or pattern of an object) and (b) physical (i.e., knowledge about the lawful ways that objects move and interact). However, whether infants demonstrate this ability depends on the task used. When an event monitoring task is used (i.e., infants must judge whether successive portions of an event are consistent), infants demonstrate the ability to use featural information by 4.5 months of age, and some forms of physical information by 3.5 months of age (Aguiar & Baillargeon, 1997; Wilcox & Baillargeon, 1997). In contrast, when an event mapping task is used (i.e., infants must retrieve a representation of one event and compare it to a subsequent event), older infants often fail (Wilcox & Baillargeon, in press; Xu & Carey, 1996). The goal of the proposed research is to examine more closely the mapping problem and to identify the processes that infants engage in when they attempt to retrieve representations of occlusion events. The proposed research has been organized into two sections. The first section investigates infants ability to map occlusion events that involve two featurally distinct objects. These experiments address the question of how infants organize and map events that require binding features to individuals. The second section investigates infants ability to map occlusion events that involve two identical objects. These experiments address two issues: (a) infants ability to draw on different forms of physical knowledge to individuate objects and (b) event ambiguity and how it contributes to mapping difficulties. Together, the results of the proposed research will provide new insight into the way that infants form representations of occlusion events and how infants use these representations when reasoning about other physical events. The results will also provide direction for future research that will focus on the investigation of event representations in infancy.